Finally properly fixed getMouseButton
Finally properly fixed getMouseButton

+ onMouseDrag now only captures mouseUp on the element to which it is bound (fix for IE).

bertrand-caron/OFraMP,bertrand-caron/OFraMP,jimivdw/OFraMP,bertrand-caron/OFraMP,jimivdw/OFraMP,bertrand-caron/OFraMP